Lacrimal gland ductal carcinomas: Clinical, Morphological and Genetic characterization and implications for targeted treatment

Primary Ductal Her-2 Positive Adenocarcinoma of Salivary Gland: A Long Follow-Up Case Report and Review of the Literature

Background: Epithelial tumors of lacrimal glands are rare and primary ductal adenocarcinoma of the lacrimal gland accounts for only 2% of all epithelial lacrimal gland tumors. Considering its rarity and lack of uniform diagnostic criteria, treatment protocols are not well defined. In this study, we describe a Her-2 positive case and review previously reported cases. Methods: In 2012, a 42-year-old woman affected by primary ductal adenocarcinoma of the lacrimal gland was treated with transpalpebral anterior orbitotomy and adjuvant radiotherapy. In July 2013, she presented local relapse and she underwent orbital exenteration. In November 2013, for neck nodal progression, seven cycles of chemotherapy (cisplatin and epirubicin) associated with a humanized monoclonal antibody-targeting HER 2 therapy (trastuzumab and pertuzumab) were performed, with a marked response rate. Then, she underwent total parotidectomy with right neck lymphadenectomy and adjuvant hadrontherapy. Results: Nine years later (113 months) after treatment completion, the patient was alive without disease and with acceptable toxicity. Conclusions: In primary ductal adenocarcinoma of the lacrimal gland, early diagnosis and multimodal treatments could be crucial, considering its often aggressive tendency. Considering the lack of treatment guidelines, case report recording can be useful in patient management.

Lacrimal Gland Adenocarcinoma Clinicopathologic Features and Outcomes Compared With Those of Lacrimal Gland Adenoid Cystic Carcinoma

PURPOSE

Lacrimal gland (LG) adenocarcinomas (ACs) are rare, with limited data. We compared clinicopathologic features and local recurrence, distant metastasis, and survival rates between LG AC and LG adenoid cystic carcinoma (ACC).

METHODS

The records of LG AC patients treated from 2008 to 2022 and LG ACC patients treated from 1998 to 2022 at the same center were retrospectively reviewed.

RESULTS

The study included 20 patients with AC; 10 de-novo AC, 10 ex-pleomorphic AC; and 51 ACC patients. The median age at diagnosis was 61 years for de-novo AC, 54 years for ex-pleomorphic AC, and 45 years for ACC. All groups had male predominance. The initial T category was T2 in 50% (5/10) of de-novo ACs; 60% (6/10) of ex-pleomorphic ACs; and 59% (30/51) of ACCs. Perineural invasion was present in 33% (5/15) of ACs and 90% (45/50) of ACCs ( p < 0.001). Of the 20 AC patients, 14 had eye-sparing surgery; 4 had orbital exenteration; and 2 had unresectable disease. All AC patients received postoperative radiotherapy and 15 (75%) received concurrent chemotherapy. Fourteen AC patients were tested for human growth factor receptor 2 expression, and 10 (71%) were human growth factor receptor 2 positive; 5 received human growth factor receptor 2-targeted therapy. AC and ACC had similar 5-year recurrence rates (20% and 33%, respectively, p = 0.31) and metastasis rates (20% and 34%, respectively, p = 0.30). de-novo AC, ex-pleomorphic AC, and ACC had similar 5-year disease-specific survival rates (80%, 79%, and 81%, respectively, p > 0.99).

CONCLUSIONS

LG AC and ACC have similar baseline clinicopathologic features, except that perineural invasion is more common in ACC, and similar recurrence, metastasis, and survival rates. Human growth factor receptor 2-targeted therapy may be appropriate in some patients with LG AC.

The poor prognosis of lacrimal gland adenocarcinoma: a clinical study and literature review

PURPOSE

The incidence of lacrimal gland adenocarcinoma is low. This study was designed to analyze the clinical and prognostic characteristics of lacrimal gland adenocarcinoma.

METHODS

This was a clinical study and literature review; 25 patients diagnosed with lacrimal gland adenocarcinoma by histopathology were enrolled and their medical history data were collected.

RESULTS

The incidence of bone destruction and surrounding tissue invasion was 52% and 44%, respectively. The incidence of distant metastasis of lacrimal gland adenocarcinoma was about 50%. The 5-year overall survival rate of death or metastasis was 33.5%. Age, sex, laterality, tumor size, pathology type, bone destruction, nerve or perineural invasion, invasion of peripheral tissue, T stage, AR, Her-2 and treatment had no significant correlation with lacrimal adenocarcinoma's prognosis (P > 0.05), while the higher expression of Ki-67 may have higher risk of death or metastasis (P = 0.020).

CONCLUSION

The incidence of bone destruction and distant metastasis of lacrimal adenocarcinoma is high and the imaging examination is necessary to assess the risk of distant metastasis. The 5-year survival rate of death or metastasis is 33.5% and the high expression of Ki-67 predicts poor prognosis of lacrimal adenocarcinoma.

Molecular characterisation of tumours of the lacrimal apparatus

AIMS

Malignant tumours of the lacrimal apparatus are rare and frequently show a poor prognosis, with no clear therapeutic standards. Characterisation of the genetic landscape of these rare tumours is sparse, and therefore therapeutics generally follow those of their common salivary gland counterparts. To further clarify the pathophysiology and discover potential therapeutic targets, we investigated the genetic landscape of eight tumours of the lacrimal apparatus.

METHODS AND RESULTS

DNA and RNA sequencing were performed to identify genetic mutations and gene fusions. Immunohistochemistry, fluorescence in-situ hybridisation and reverse transcription-polymerase chain reaction followed by Sanger sequencing were performed to confirm the identified molecular alterations. Genetic alterations were detected in six tumours. Among five adenoid cystic carcinomas (ACC), four had confirmed alterations of MYB or MYBL1 genes, including a MYB::NFIB fusion, a MYBL1::NFIB fusion, a MYB amplification and a novel NFIB::THSD7B fusion. Mutations in genes encoding epigenetic modifiers, as well as NOTCH1, FGFR2 and ATM mutations, were also identified in ACCs. A carcinoma ex pleomorphic adenoma showed TP53 and CIC mutations and an amplification of ERBB2. A transitional cell carcinoma was associated with HPV16 infection. No genetic alteration was found for one adenocarcinoma, not otherwise specified.

CONCLUSIONS

Our study highlights the variety of molecular alterations associated with lacrimal system tumours and emphasises the importance of molecular testing in these tumours, which can reveal potentially targetable mutations. Our results also reinforce the hypothesis of a common physiopathology of all ACCs, regardless of their primary location.

Rare Diseases of the Orbit

This article provides an overview of rare orbital diseases. Congenital malformations, inflammatory diseases, benign and malignant neoplasias are described. Although it represents a relatively small area of the body the orbit contains multiple different tissues. Therefore, a great variety of diseases can be found within the orbital space. That is the reason, why both the completeness and the level of detail in the description of particular diseases must be somewhat limited. Nevertheless, clinical manifestations, important aspects of diagnosis, treatment strategies, and, when specific data are available, the prognosis are described. The authors tried to highlight the most characteristic aspects of the different diseases to describe their relevant aspects in spite of the brevity of the subsections.

Primary De novo ductal adenocarcinoma of the lacrimal gland

BACKGROUND

Primary ductal adenocarcinoma of the lacrimal gland is a rare and aggressive malignant epithelial lacrimal gland neoplasm, morphologically and phenotypically resembles salivary duct carcinoma, and both strongly resemble infiltrating ductal carcinoma of breast.

METHOD

Retrospective Chart review of cases of malignant lacrimal gland tumors from 2013 July to 2020 July. Authors describe the clinico radiological, morphological and immunohistochemical features of primary ductal adenocarcinoma (PDA) of lacrimal gland. Extensive review of literature of PDA of lacrimal gland and salivary gland ductal carcinoma has been performed.

RESULTS

Retrospective chart review of the last 7 years yielded 22 malignant lacrimal gland neoplasms of which 4 cases demonstrated features of primary ductal adenocarcinoma of lacrimal gland, 2/4 cases showed an evidence of a pre existing pleomorphic adenoma and 2 were found to be de novo ductal adenocarcinomas. PDA of lacrimal gland showed expression of CK7, CK19, AR, HER2, cyclin D1 and were negative for CK5/14, CK 20, ER, PR, PSA, TTF-1, S-100 and SMA. Expression of GCDFP-15 was noted in one case. The presence of multiple events of loco-regional recurrences and/or distant metastasis necessitated a multidisciplinary approach.

CONCLUSIONS

Authors have expressed the need of clinical correlation; thorough tissue sampling and extensive immunohistochemical work up in identification of de novo PDA's and their molecular subtypes. A multi-institutional study might help in formulating the diagnostic criteria, identification of actionable targets, and thus study the role of targeted therapy in this rare and aggressive tumor which may result in better patient outcomes.

Ductal Adenocarcinoma Ex Pleomorphic Adenoma of the Lacrimal Gland: a Rare and Morbid Malignancy

Carcinoma ex pleomorphic adenoma (Ca ex PA) is a rare malignant transformation of a benign primary pleomorphic adenoma (PA). We report the case of a 62-year-old male who presented with a swelling over his left temple. Imaging revealed a lytic lesion over the left orbital wall with soft tissue extension suggestive of malignancy. He underwent an en bloc resection of the mass with orbital exenteration, craniotomy, and reconstruction. Pathology demonstrated a lacrimal gland ductal adenocarcinoma arising from a PA which led to the diagnosis of ductal adenoCa ex PA. Postoperatively, he received chemotherapy with 6 cycles of cisplatin and concurrent radiation therapy (RT), but his course was complicated by recurrent bacterial meningitis and abscesses and he ultimately opted for comfort measures. Patients with PA of the lacrimal gland experience an insidiously enlarging painless swelling of the orbit with transformation to Ca ex PA highlighted by a rapid onset of bulbar enlargement, displacement, and often proptosis. Ductal adenoCa ex PA is aggressive with a poor prognosis and has no established standard of care. This case highlights the rarity of this condition and the need for more literature to help direct treatment.

Primary ductal adenocarcinoma of the lacrimal gland: A review and report of five cases

Primary ductal adenocarcinoma (PDA) is a rare epithelial tumor of the lacrimal gland. Herein we report 5 cases and review 29 published cases of PDA of the lacrimal gland. Among these 5 cases, the most common clinical presentation was painless swelling and/or proptosis of their eye. The size of the lesions ranged from 1.6 to 2.5 cm. Histopathologic examination revealed proliferations of ductal or gland-like cells with vesiculated pleomorphic nuclei and prominent nucleoli. Tumor cells stained positive for epithelial and apocrine differentiation markers. Immunohistochemistry for human epidermal growth factor 2 was positive in 2 of the 4 cases. Four of the five patients were alive at the last follow-up visit. One died with bone metastases, which were diagnosed 25 months after exenteration and then survived an additional 51 months. On reviewing of twenty-nine previously published cases of PDA, the mean age of diagnosis was 58 years, with a male predominance (75%). Fifteen patients (54%) had distant metastases, 1 (4%) had local recurrence, and 10 (37%) suffered from a PDA-related death. PDA is a high-grade aggressive epithelial tumor of the lacrimal gland. Although rare, awareness and recognition of this malignancy are important to help determine prognosis and treatment options.

Intracapsular High-Grade Ductal Carcinoma In-Situ Ex Pleomorphic Adenoma of the Lacrimal Gland

Primary ductal adenocarcinoma of the lacrimal gland is an aggressive neoplasm and can be seen either as a de novo malignancy or in the setting of a carcinoma ex pleomorphic adenoma. Carcinoma ex pleomorphic adenoma carries an overall unfavorable outcome; however, prognosis depends on the type and grade of the malignant component, presence of retained myoepithelial component, and extend of invasion beyond the capsule. Herein, the authors describe a 78-year-old man diagnosed with an incidental, intracapsular, high-grade ductal adenocarcinoma in situ ex pleomorphic adenoma, who is free of disease at 9 months subsequent to complete resection. It is important to recognize the morphologic features of intraductal and intracapsular neoplasms to prevent unnecessary morbidities due to extensive surgical interventions or radiotherapy.Morphologic features of intracapsular ductal carcinoma in situ ex pleomorphic adenoma, which shows better clinical outcomes with complete excision than its invasive counterpart.

A Case of Lacrimal Gland Ductal Carcinoma With Regional Lymph Node Metastasis

Ductal carcinoma of the lacrimal gland is a very rare and aggressive neoplasm, with clinical and histopathologic similarities to salivary ductal carcinoma. Of the 25 previously reported cases, 2 patients had metastases to local lymph nodes confirmed on pathologic examination. The authors now report the clinical presentation, histopathologic and immunohistochemical features, and the treatment of a third patient with lacrimal gland ductal carcinoma with spread to local lymph nodes. In contrast to ductal carcinoma, lymph node involvement has not been reported in the largest series of adenoid cystic carcinoma, a much more common lacrimal gland malignancy. This case highlights the need for possible lymph node surveillance in patients with lacrimal gland ductal carcinoma.

An update on head and neck cancer: new entities and their histopathology, molecular background, treatment, and outcome

The head and neck region harbor numerous specialized tissues of all lineages giving rise to a plethora of different malignancies. In recent years, new types and subtypes of cancer has been described here due to the recognition of their histological and molecular characteristics. Some have been formally accepted in the most recent classifications from the World Health Organization (WHO) and American Joint Committee on Cancer (AJCC) as distinct diseases due to characteristics in clinical presentation, outcome, and treatment. In particular, this applies to malignancies of the salivary gland, sinonasal tract, and oropharynx. In this overview, we present the most recent developments in the classification, histopathological characteristics, and molecular features of head and neck cancer. The clinical and radiological characteristics, outcome, and treatment options including perspectives for targeted therapies, are discussed.

Recurrent rearrangements of the PLAG1 and HMGA2 genes in lacrimal gland pleomorphic adenoma and carcinoma ex pleomorphic adenoma

PURPOSE

Lacrimal gland tumours constitute a wide spectrum of neoplastic lesions that are histologically similar to tumours of the salivary gland. In the salivary gland, pleomorphic adenoma (PA) is frequently characterized by recurrent chromosomal rearrangements of the PLAG1 and HMGA2 genes, a genetic feature retained in carcinoma ex pleomorphic adenoma (ca-ex-PA) that makes it possible to distinguish ca-ex-PA from de novo carcinomas. However, whether PLAG1 and HMGA2 gene rearrangements are found in lacrimal gland PA and ca-ex-PA is not known.

METHODS

Twenty-one lacrimal gland PAs and four ca-ex-PAs were retrospectively reviewed and subjected to break-apart fluorescence in situ hybridization (FISH) for rearrangements of the PLAG1 gene. Cases without PLAG1 abnormalities were subjected to HMGA2 break-apart FISH. Immunohistochemical staining for PLAG1 and HMGA2 protein was performed and correlated with gene status.

RESULTS

Sixteen of 21 PAs showed rearrangement of PLAG1 and were all positive for PLAG1 protein. Two of the remaining five PAs showed rearrangement of HMGA2 and were the only cases positive for HMGA2 with immunohistochemistry. The three FISH-negative PAs expressed PLAG1 protein. All four ca-ex-PAs showed rearrangement of PLAG1 and expressed PLAG1 protein. None of the de novo carcinomas showed rearrangement of either of the two genes or expression of the two proteins.

CONCLUSION

Rearrangement of PLAG1 and HMGA2 and expression of the corresponding proteins are frequent and specific findings in lacrimal gland PA and ca-ex-PA. The mechanism for PLAG1 overexpression in FISH-negative PAs is yet to be clarified.

Primary Secretory Carcinoma of the Lacrimal Gland: Report of a New Entity

PURPOSE

Secretory carcinoma has been described in the breast, salivary glands, skin, and other organs, but has not been reported in the lacrimal gland to date. Since lacrimal and salivary glands show similar tumors, we hypothesized that lacrimal secretory carcinoma may exist but has been misclassified in the past.

DESIGN

We undertook a retrospective review of all lacrimal gland tumors at 2 tertiary institutions with centralized ocular pathology practices.

METHODS

A total of 350 lacrimal tumors were reviewed by the authors. Candidate tumors were tested for ETV-NTRK rearrangement by fluorescence in situ hybridization and the presence of the translocation was confirmed by next-generation sequencing.

RESULTS

We identified a single case of secretory carcinoma. The diagnosis was confirmed by demonstrating specific immunohistochemical profile and the presence of ETV6-NTRK3 gene fusion, which is characteristic of secretory carcinoma of other sites. The tumor occurred in a young man who was treated with surgery alone with no recurrence during 12 years of follow-up.

CONCLUSION

Secretory carcinoma is a new lacrimal gland carcinoma type that should be added to the spectrum of low-grade lacrimal gland tumors.

Lacrimal gland adenocarcinoma responding to checkpoint inhibition and androgen deprivation

Although the histologically diverse classification of salivary gland tumors can be successfully applied to the epithelial lacrimal gland neoplasms, it is not clear whether the molecular makeup differs between these two different tumor types. Adenocarcinomas have known to have driver mutations in non-small cell lung cancer, however, besides HER2 expression not much is known regarding molecular drivers in lacrimal tumors. Androgen receptor (AR) expression and deprivation combined with checkpoint inhibition (CPI) have not been described before in lacrimal gland adenocarcinoma. To our knowledge, this is the first case report describing a prolonged response to CPI and AR inhibitors.

Adenoid cystic carcinomas of the salivary gland, lacrimal gland, and breast are morphologically and genetically similar but have distinct microRNA expression profiles

Adenoid cystic carcinoma is among the most frequent malignancies in the salivary and lacrimal glands and has a grave prognosis characterized by frequent local recurrences, distant metastases, and tumor-related mortality. Conversely, adenoid cystic carcinoma of the breast is a rare type of triple-negative (estrogen and progesterone receptor, HER2) and basal-like carcinoma, which in contrast to other triple-negative and basal-like breast carcinomas has a very favorable prognosis. Irrespective of site, adenoid cystic carcinoma is characterized by gene fusions involving MYB, MYBL1, and NFIB, and the reason for the different clinical outcomes is unknown. In order to identify the molecular mechanisms underlying the discrepancy in clinical outcome, we characterized the phenotypic profiles, pattern of gene rearrangements, and global microRNA expression profiles of 64 salivary gland, 9 lacrimal gland, and 11 breast adenoid cystic carcinomas. All breast and lacrimal gland adenoid cystic carcinomas had triple-negative and basal-like phenotypes, while salivary gland tumors were indeterminate in 13% of cases. Aberrations in MYB and/or NFIB were found in the majority of cases in all three locations, whereas MYBL1 involvement was restricted to tumors in the salivary gland. Global microRNA expression profiling separated salivary and lacrimal gland adenoid cystic carcinoma from their respective normal glands but could not distinguish normal breast adenoid cystic carcinoma from normal breast tissue. Hierarchical clustering separated adenoid cystic carcinomas of salivary gland origin from those of the breast and placed lacrimal gland carcinomas in between these. Functional annotation of the microRNAs differentially expressed between salivary gland and breast adenoid cystic carcinoma showed these as regulating genes involved in metabolism, signal transduction, and genes involved in other cancers. In conclusion, microRNA dysregulation is the first class of molecules separating adenoid cystic carcinoma according to the site of origin. This highlights a novel venue for exploring the biology of adenoid cystic carcinoma.

Genetic rearrangements, hotspot mutations, and microRNA expression in the progression of metastatic adenoid cystic carcinoma of the salivary gland

Adenoid cystic carcinoma (ACC) is among the most common salivary gland malignancies, and is notorious for its unpredictable clinical course with frequent local recurrences and metastatic spread. However, the molecular mechanisms for metastatic spread are poorly understood. This malignancy is known to frequently harbor gene fusions involving MYB, MYBL1, and NFIB, and to have a low mutational burden. Most studies have focused on primary tumors to understand the biology of ACC, but this has not revealed a genetic cause for metastatic dissemination in the majority of cases. Hence, other molecular mechanisms are likely to be involved. Here, we characterize the genetic and microRNA expressional landscape of primary ACC and corresponding metastatic lesions from 11 patients. FISH demonstrated preservation of MYB aberrations between primary tumors and metastases, and targeted next-generation sequencing identified mutations exclusive for the metastatic lesions in 3/11 cases (27.3%). Global microRNA profiling identified several differentially expressed miRNAs between primary ACC and metastases as compared to normal salivary gland tissue. Interestingly, individual tumor pairs differed in miRNA profile, but there was no general difference between primary ACCs and metastases. Collectively, we show that MYB and NFIB aberrations are consistently preserved in ACC metastatic lesions, and that additional mutations included in the 50-gene hotspot panel used are infrequently acquired by the metastatic lesions. In contrast, tumor pairs differ in microRNA expression and our data suggest that they are heterogeneous according to their microRNA profile. This adds an additional layer to the complex process of ACC metastatic spread.

Efficacy and safety of carbon-ion radiotherapy for lacrimal gland carcinomas with extraorbital extension: a retrospective cohort study

Purpose

To evaluate the efficacy and safety of carbon-ion radiotherapy (CIRT) for patients with lacrimal gland carcinomas (LGCs) with extraorbital extension.

Results

The median follow-up period was 53.7 months. The 5-year local control and overall survival rates were 62% and 65%, respectively. Regarding late toxicities, 12 patients (36.4%) developed Grade 4 optic nerve disorders, including visual losses of the diseased side (N = 8; 66.7%), and 1 patient (3.0%) developed a Grade 3 optic nerve disorder. Three patients (9.0%) developed Grade 3 cataracts, 3 (9.0%) developed glaucoma, and 1 (3.0%) developed retinopathy. Two patients (6.1%) had Grade 4 central nervous system necrosis. No Grade 5 late toxicities were observed. The 5-year preservation rate of the ipsilateral eyeball was 86%.

Conclusion

Definitive CIRT is effective for LGCs with extraorbital extension with acceptable toxicity.

Methods

Thirty-three patients treated with CIRT at our institution were analyzed. Sixteen patients (48.5%) had adenoid cystic carcinoma, 8 (24.2%) had adenocarcinoma not otherwise specified, and 9 (27.3%) had other types of the disease. Thirty patients (90.9%) had T4c tumors. The prescribed doses were 57.6 Gy (relative biological effectiveness [RBE]) (N = 18; 54.5%) and 64.0 Gy (RBE) (N = 15; 45.5%) in 16 fractions.

Primary ductal adenocarcinoma of lacrimal gland: Two case reports and review of the literature

A 64-year-old male presented with progressive proptosis of the left eye for 3 months. Orbital computed tomography (CT) demonstrated a 3.9 cm infiltrative mass over the superotemporal quadrant of the left orbit. Pathology of biopsy revealed a ductal adenocarcinoma of lacrimal gland with positive immunohistochemical staining for androgen receptor (AR), cytokeratin-7 (CK7), and gross cystic disease fluid protein 15 (GCDFP-15). The patient received orbital exenteration and adjuvant chemoradiotherapy. No recurrence or metastasis was noted 27 months after treatment. Another case was a 64-year-old male who came for proptosis of the right eye and diplopia for 3 weeks. Orbital CT revealed a 5 cm infiltrated right superotemporal orbital mass with destruction of the lateral and inferior orbital walls. Biopsy showed primary ductal adenocarcinoma of lacrimal gland with positive immunohistochemical staining for CK7, AR, and epidermal growth factor receptor. The patient underwent exenteration and concomitant chemoradiotherapy. However, lung and neck metastasis was noted 21 months after surgery. Collectively, 26 cases in the literature were reviewed. The mean age was 57 years old and male was prevalent (73%). Most immunohistological staining showed positive for AR (46%), CK7 (46%), Ki-67 (38%), and GCDFP-15 (35%). More than half of the patients developed metastasis and one-third of the patients died of disease. Early diagnosis, treatment, and long-term follow-up are required for this aggressive tumor.

ETV6 Gene Rearrangements Characterize a Morphologically Distinct Subset of Sinonasal Low-grade Non-intestinal-type Adenocarcinoma: A Novel Translocation-associated Carcinoma Restricted to the Sinonasal Tract

Low-grade sinonasal adenocarcinomas (low-grade SNACs) of the sinonasal tract comprise a poorly characterized and histologically heterogeneous group of tumors. We describe three cases of a histologically distinct variant of low-grade SNAC characterized by ETV6 gene rearrangements. The patients included 2 women (aged 32 and 88 y) and a man (aged 75 y); all were initially treated with surgery alone. Follow-up ranged from 9 to 170 months with one patient having 2 local recurrences and none experiencing distant or regional metastases. Tumors were composed of cytologically bland columnar and cuboidal eosinophilic tumor cells with basally located nuclei arranged in tubular and tubulotrabecular patterns. Immunohistochemically, CK7, DOG1, GCDFP-15, and SOX10 were positive in all cases, and vimentin was positive in 2 cases. Scattered single cells or small groups of tumor cells were S-100 positive. Only one case had weak, focal expression of GATA3, and mammaglobin was consistently negative. Two cases had ETV6-NTRK3 gene fusions, whereas ETV6 had an unknown fusion partner gene in one case. The highly similar morphology, immunohistochemical profile, and genetics of the presented cases are suggestive of a specific disease. Although translocation-associated adenocarcinomas in the sinonasal tract have previously been described exclusively as salivary-type carcinomas, we present the first type of carcinoma characterized by recurrent genetic rearrangements and distinct phenotype occurring exclusively in the sinonasal tract with no known major salivary gland counterpart. We provisionally designate this tumor ETV6-rearranged low-grade SNAC. Identification of additional cases is necessary to fully appreciate the morphologic and biological spectrum of this disease.

AR-Signaling in Human Malignancies: Prostate Cancer and Beyond

In the 1940s Charles Huggins reported remarkable palliative benefits following surgical castration in men with advanced prostate cancer, and since then the androgen receptor (AR) has remained the main therapeutic target in this disease. Over the past couple of decades, our understanding of AR-signaling biology has dramatically improved, and it has become apparent that the AR can modulate a number of other well-described oncogenic signaling pathways. Not surprisingly, mounting preclinical and epidemiologic data now supports a role for AR-signaling in promoting the growth and progression of several cancers other than prostate, and early phase clinical trials have documented preliminary signs of efficacy when AR-signaling inhibitors are used in several of these malignancies. In this article, we provide an overview of the evidence supporting the use of AR-directed therapies in prostate as well as other cancers, with an emphasis on the rationale for targeting AR-signaling across tumor types.